I have been very hesitant to write this article for a number
of reasons. Various other writers have described lambic
beers and the brewing of them in much more eloquent terms
than I could ever hope to. Michael Jackson comes to mind
first and foremost as the person responsible for bringing
lambic out of obscurity through writing, TV and even CD
ROM. (1, TV, CD-ROM). Another key writer on the subject,
from the homebrewer's perspective, is J.X. Guinard with his
book “Lambic” (2). This is considered the definitive guide
for anyone thinking about making lambic-style beer outside
Belgium. And recently Martin Lodahl has written some very
inspiring articles on the subject (3,4). Following in the
footsteps of such articulate writers seems an almost
insurmountable task. Also I have not been to Belgium and do
not live in what is considered a beer Mecca.

For me, the purpose of this article is to organize and
present some of the various information and scientific
research on how lambic is made in Belgium, and how you can
make beer in the style of lambic at home. The information I
will present in this article is a condensation of material
from various sources. These include research papers and
dissertations from Belgium, articles written by various
other authors, “Lambic” by Guinard, personal accounts from
people who have been to lambic breweries, postings from the
internet Lambic Digest and my own personal experiences. I
hope to provide accurate information that will aid you in
your attempts to make lambic-style beer.

First off, I will do my best to refrain from using the word
lambic to describe any beer made outside Belgium. Lambic is
only made in a small area outside Brussels, even though one
American craft brewer might have you thinking otherwise.
In my discussion of making similar beer by the homebrewer I
prefer to use the term lambic-style. On the internet lambic
Digest one sees the term plambic being used, which is short
for pseudo-lambic. Again with the point being that real,
true lambic is only made in Belgium and nowhere else. If
you find this view extreme I hope that reading this article
and some of the other writings cited here will help change
your mind.

I will not delve deeply into the history of lambic here as
it has been covered adequately elsewhere (1,2,3). Suffice
it to say that lambic is probably one of the oldest styles
of beer still made today. The problem now is that lambic
brewing is in danger of ceasing to exist. This is due to
the changing European economic market, changes in consumer
preferences, and the artisanal nature of lambic brewing.
It will be a sad day when beers like Cantillon are no
longer available.

I live for lambic some would say. In preparing this article
I seemed to spend all my spare time reading and re-reading
and taking notes from the various technical publications,
articles and books I have on the subject of lambic. Being
a scientist in real life I have tried to do a complete
analysis of all aspects of the process of lambic
production. From wort production to fermentation to
blending and bottling. My goal has been to try to decipher
the lambic brewing process and what aspects may or may not
be important to the homebrewer trying to make a similar
style beer.

Lambic is made by what many consider an anachronistic
process. The grist is made up of 30-40% raw unmalted wheat
with the remainder being malted barley. The mashing
process is carried out using a technique called turbid
mashing. Unlike decoction mashing the liquid portion of the
mash is removed and boiled, leading to poor conversion and
large amounts of unconverted starch ending up in the
finished wort. Whereas most brewers want the freshest hops,
lambic brewers use hops that have been stored in the open
for 2-3 years. The wort itself is not inoculated with a
pure strain of yeast. Instead the brewer allows the wort to
cool overnight in open cool ships. This way any
microorganism in the brewery can get into the wort and
grow. These organisms include various bacteria and wild
yeast. And finally, the beer is fermented not in stainless
steel but in oak casks for upwards of 3 or more years
before bottling. So as you can see lambic is not your
ordinary beer.

These are the essential defining characteristics of real
lambic. Again, as homebrewers we do not have to follow
tradition to the letter. We do not live in Belgium and
most of us have not been making beer by this method for
hundreds of years. But also remember that these points
only define lambic in the broadest sense. They do not
provide insight into the nuances involved in obtaining a
product of the character and flavor profile of a Cantillon
Rose de Gambrinus or a Boon vintage dated Mariage Parfait.

I have always felt this quotation by Michael Jackson really
describes how I feel about lambic beer. “The lambic family
are not everybody’s glass of beer, but no one with a keen
interest in alcoholic drink would find them anything less
than fascinating. In their “wildness” and
unpredictability, these are exciting brews. At their best,
they are the meeting point between beer and wine. At their
worst, they offer a taste of history.”(2)

Quite often people are quite shocked by the extreme flavor
profile of lambic or my attempts at recreating the style.
Too often people immediately dismiss the beer as
undrinkable and infected without really “tasting” the beer.
Of course this reaction is not unlike the that of a
hard-core Budweiser drinker tasting a beer like Chimay for
the first time.

Making a lambic-style beer at home can be as simple as
boiling up some extract with hops and adding a few yeast
and bacteria cultures. Or one can go to extremes using
traditional turbid mashing schedules, spontaneous
fermentation and aging in oak casks. As a homebrewer you
have many choices available. But based on my experience do
not expect to have a product of similar character to any of
the real lambics in a few weeks or even months. It will
take years!

Using the various resources at my disposal I have a very
general idea how lambic is made in Belgium. Remember
lambic making is an artisanal craft and the brewers are
somewhat secretive about giving exact details of how they do
things. Most Belgian brewers seem to be willing to “make
up” an answer rather than give none at all. And because it
is a craft, there is a great deal of experiential knowledge
involved which one can not learn by simply following a
recipe. So remember this information is only very general
and should not be taken as the gospel truth.

Making lambic-style ale requires a great deal of patience.
Most homebrewers who want to make such a beer think that
because they can make a regular ale in a few weeks that
they should also be able to make a lambic like beer in the
same period of time or maybe a little longer. Many brewers
expect that within a few months they will have a product
that is ready to bottle and that after that it will be ready
to drink in another few weeks. I have seen this view
expressed on the internet and also in the recipes I have
seen from the AHA National Homebrew Competition.
Unfortunately the recipe section of “Lambic” (2) does
little to dispel this belief. Real lambic is not made in a
few weeks or months. It takes years for it to become the
complex product you find in the bottle. There is no magic
formula for “instant” lambic-style ale. The microorganisms
used in the fermentation grow very slowly and are equally
slow at producing the flavor profile that gives a product
that has depth of character.

Do not think that a few months is enough time to make such a
beer. I feel you need to wait at least a year before you
even consider bottling the beer or adding fruit to it. If
you are not prepared to wait this long then I suggest you do
not try in the first place. This may seem like an extreme
view, and it is, but lambic-style beer making is not
something I take lightly. You must be prepared to fail even
after investing a great deal of time and effort in the
production of such a beer. Don’t “imagine” the beer
developing a pellicle, ropiness or Brettanomyces character.
Either it will or it will not. There is very little you
can really do to change what ultimately happens in the
fermentation vessel.

You can use traditional mashing techniques, use all the
right ingredients and add all kinds of wild yeast and
bacteria, ferment in a cask for years and still end up with
a totally disappointing product. Do not say you were not
warned. Your beer may end up so acidic you will want to
use it for cleaning calcium deposits off of your brew
kettle or it may be so mild that it barely passes as
infected beer. And even after bottling, the beer can
undergo large changes in flavor. So be prepared for a large
amount of uncertainty all along the way.

Give up any notion that you are going to make a product like
Boon or Cantillon even with a great deal of experience.
You cannot buy a kit or follow some recipe in a homebrew
shop catalog and end up with a well balanced, complex
product. Your beer is not going to develop Brettanomyces
character, nor will it develop the proper acidity in a few
weeks. It will not develop a melange of flavor after two
weeks in the bottle. Am I making myself clear? The path
to the Holy Grail may take a lifetime. Now having said all
this I still feel that with a bit of effort and patience
anyone can produce a reasonable lambic-style ale in the
home setting.

Some comments on Lambic by Guinard

By far the most complete and really only book available to
the homebrewer on lambic beer brewing is “Lambic” by J.X.
Guinard.(2) This book describes all aspects including the
history of lambic brewing, traditional processes and the
breweries that still make this style of beer. It also goes
into a fair amount of detail outlining the microbiology of
spontaneous fermentation and how to go about making a pure
culture lambic-style ale at home. The information in the
book is accurate and concise except for a few minor
details. For example I have yet to find a reference that
indicates that Kloeckera apiculata have any proteolytic
activity as described in the book.

Having spoken to Dr. Guinard I realize the he felt the
recipe section could not possibly do justice to this style
of beer. Also he was working within the constraints of
what was considered practical for the average homebrewer. I
think most brewers who have tried to make pure culture
lambic-style beer will agree that the times he suggests for
fermentation and bottle conditioning are far too short to
achieve a product with a character truly similar to the
real thing. He suggests that a few weeks of fermentation
and a few weeks of bottle conditioning are all that is
required to achieve a beer with lambic-like flavor. As
stated, myself and others would largely disagree with this
assertion. At the same time I think he and Brewers
Publications realized that few homebrewers would even think
about buying a book that had recipes that suggested the
beer be allowed to ferment for a year or two and then
undergo bottle conditioning for another year or more.

But of course those of us who have pursued this type of
brewing have found this book to be an invaluable resource
and an excellent stepping stone. Using it as a guide we
have been able to locate other sources of information and do
testing on our own. We have found that the traditional
fermentation and aging process is indeed necessary to
achieve a truly characterful beer. We have learned an
appreciation for the craft of lambic brewing and the fact
that it is a dying art. I highly recommend “Lambic” (2) to
anyone considering making pure culture lambic-style beer.
Just keep in mind that you are better off getting the beer
started and then forgetting about it for a year or two.
Great beer is not something that can be rushed.

A traditional lambic grist is composed of 30-40% raw wheat
with the remainder being either 2 row or a combination of 2
and 6 row barley. Using this grist composition will give a
wort that is high in amino acids and dextrins and light in
color.

The simplest approach to making lambic-style ale is to use
extract, either dry or liquid. Since you want and need
extra amino acids and dextrins in the wort to support the
long fermentation you should consider using an extract meant
for making wheat beer. These are typically made from
60-70% malted wheat and are readily available in liquid and
dried form. You can also blend the wheat extract with
malted barley extract to achieve a 30-40% wheat content.
You might also consider buying some 100% wheat extract and
blending it with malt extract at the more traditional
30-40% range. The 1994 AHA Homebrewer of the Year brewed
his lambic-style beer using the wheat based extract
produced by Briess. So do not despair thinking that you
can only make lambic-style beers if you are an all grain
based brewer. You should get the freshest extract possible
and carry out the boil for a full hour to maximize the
extraction of the hop antiseptic compounds and to
precipitate the excess proteins in the extract. The main
problems with extracts as a whole are that they generally
produce beers darker than equivalent all grain beers and the
extracts themselves may be somewhat nutrient deficient
(5,6).

If you are an all grain brewer you have a number of options
available. You can choose to use malted, flaked or raw
wheat in your mash as well as performing various mash
routines. Probably the simplest mash consists of 30-40%
malted wheat with the remainder being made up of 2 row pils
or lager malt. This can then be mashed using a single step
infusion mash in the 150-155 F (65-68 C) range. This will
produce a reasonable dextrinous wort that is also very light
in color. Or you could also modify the mash schedule using
a step mash or decoction mash of the type outlined by
Warner(7). Such a mash technique helps break down the
excess wheat proteins and provides the extra amino acids
needed by the various yeast and bacteria. One problem,
though, with an intensive mash schedule is that it can lead
to too much break down of the dextrins in the grist and thus
too little carry over into the wort.

The more traditional lambic mash uses unmalted wheat, and as
with malted wheat you have a number of options available
depending on how traditional you want to be. If you are
concerned about having to take time to gelatinize the wheat
or do not want to deal with raw, ungelatinized wheat
directly in the mash, then you can choose to use flaked
wheat. Flaked wheat, also sometimes called rolled wheat,
has already been gelatinized for you. All you have to do
is add it to the grist and carry out whatever mash schedule
you feel is appropriate. Generally flaked wheat can be
found at homebrew shops or at your local natural foods'
market or co-op.

Raw wheat, in the most traditional method it is not
pre-gelatinized before being added to the mash. Because of
this, a very time consuming form of mashing is carried out
and will be discussed in more detail later. The easier
route is to grind the raw wheat and then gelatinize it
before adding it to the mash. This is accomplished by
adding water to the wheat at the rate of 1.5-2 quarts per
lb. along with 10% of the malted barley. The mixture is
heated to the 150 F (65 C) range and allowed to stand for
15-30 minutes. This allows the enzymes in the malt to act
on the wheat starch and aid in their hydration. After the
temperature rest the whole mixture is heated to boiling
with constant stirring. Feel free to add water as the
mixture begins to thicken. Be sure not to heat it too fast
or stop stirring, otherwise you will have a big gummy burnt
mess. After it has boiled for 15 minutes you can then add
it to the main mash and continue with the mashing schedule.
Add the boiled wheat to the main mash slowly with stirring
so as not to raise the temperature of the mash too quickly
or unevenly. When using this method the author prefers to
have the mash at 100 F (37 C) and then add the boiled
wheat, slowly. The temperature will settle in the 120-130
F (49-54 C) range depending on the volume. Then begin to
heat the entire mash slowly to the various step
temperatures. A fast method involves resting at 130 F (54
C) or so for 15 minutes then raising the temperature to 145
F (63 C) and holding for 15 minutes and then raising to 152
F (67 C) and holding for another 30 minutes, followed by
mash out and sparging.

The most time consuming and labor intensive method of
mashing involves what is called turbid mashing. This type
of mashing involves removing the liquid portion of the
mash, boiling it and then reintroducing it to the whole
mash. This is somewhat like the reverse of decoction
mashing in which the grain portion is removed and boiled.
A good explanation of this whole mashing process has been
provided by Guinard,(2) with further details provided
Lodahl (3). Keep in mind that lambic brewers all have
their own individual methods of turbid mashing and some do
not use turbid mashing at all.

The goal of the turbid mashing procedure is to break down
the larger proteins of the raw wheat and malt into free
amino acids and produce a wort high in dextrins and
starches. A traditional turbid mash is carried out by
mashing in and then removing the liquid portion and boiling
it and at the same time adding boiling water back to the
mash to raise the temperature. This procedure of removing
the turbid liquid, boiling it and adding boiling water to
the mash is carried out a number of times until the mash
reaches a temperature at which the addition of the boiled
turbid runnings raises it to saccharification temperature.
After a 2 hour saccharification the wort is run off and the
grains sparged with close to boiling water. Again this
whole procedure helps break down the ungelatinized raw
wheat giving one a wort high in amino acids, dextrins and
starches. The whole process is followed by a 4 to 5 hour
boil to reduce the large volume of liquid and precipitate
the excess proteins and burst any starch granules.

A simplified turbid mashing method was proposed by Frank
Boon (8). He suggested mashing in at around 86 F (30 C)
using as little as 0.5 quart of water per pound of grist.
The mash should then be stirred and the milky wort should be
run off and boiled for a few minutes. In the mean time
fresh water should be added to the grist and a step mash
performed of your choosing. After reaching the 140 F (60 C)
range the boiled milky wort is added back to the mash to
raise the temperature to the saccharification range. Then
the mash should be allowed to rest and undergo
saccharification. After this the wort should be run off and
the grain sparged. This produces a large volume of liquid
and is one of the reasons for the suggested 5 hour boil.

The sparging of a lambic mash is typically carried out with
water that is hotter than 165 F (74 C) usually closer to
190 F (88 C). This aids in extracting dextrins and
unconverted starches from the mash. This procedure also
extracts tannins from the malt as well, but these are
precipitated out or broken down over the long fermentation
cycle and do not contribute to astringency in any large
part. The use of hotter than normal sparge water is
particularly important if one follows a true turbid mash
type schedule due to the poor conversion. In normal beer
production one does not want all of these various
components extracted into the wort but in lambic brewing
they are needed to support the long fermentation process and
will ultimately be utilized by the yeast and bacteria.
Without these usually undesirable products the lambic
organisms may not thrive and produce a beer with the right
flavor characteristics.

Whether or not a turbid mash is required to achieve optimal
flavor in a lambic is a matter of debate. There are some
lambic brewers who do not use this method. But two of the
more traditional brewers, Boon and Cantillon do use it.

Be aware that you will probably not get complete starch
conversion in a mash with raw wheat regardless of how
rigorous a mash schedule you use. But this is not a
problem since you want a certain amount of unconverted
starch to carry over into the wort to provide a substrate
for the microorganisms to feed upon late in the
fermentation and maturation.

The following is a conversion of the Cantillon turbid mash
schedule to homebrew scale.(3) Based on the information
presented in the article from Brewing Techniques, the
Cantillon Brewery gets approximately 33-34 pts/lb/gallon.

The grist is composed of 34% Raw Wheat and 66% Malted
Barley. A number of assumptions have been made in scaling
down this mash schedule. It is assumed the we want to end
up with a wort with an original gravity of approximately
1.048. It was also assumed that a yield of 30
points/pound/gallon would be obtainable using this method.
As will be seen this assumption was not valid for this mash
schedule carried out using the equipment and methods
described. Your own individual results may vary.

The recipe was designed to provide 5 gallons of wort with an
original gravity of 1.048. If we assume that we can get 30
points/pound/gallon then we need a total of 240 points.

For 5 gallons you will need 240 pts total. 240 pts/30
pts/lb/gallon = 8 lbs of grain Based on this calculation we
will need 8 lbs. of grain. For a further explanation of mash
calculations see reference (9).

The Cantillon schedule calls for mashing in 1300 kg
grain/850L water (2860 lbs/900 qt) = 3.2 lbs/qt or 0.3
quarts of water/pound. We have 8 lbs of grain X 0.3 quarts
= 2.4 quarts of water. In all of the following steps the
temperature and water additions were taken directly from
the Cantillon schedule as published and scaled accordingly.

1.) In kettle #1 add water at 144 F(62 C) to the crushed
grain to achieve a temperature of 113 F (45 C) (about 2.4
quarts of water). Mix grain and water thoroughly and allow
to rest at 113 F for 10 minutes. This amount of water is
enough to just wet all the grain and flour. The mash needs
to be stirred very well to make sure all the grain is
wetted and no clumps of flour are present. Total time for
this step is about 20 minutes, with the temperature rest
included.

2.) Next, add enough boiling water (212 F)(100 C) to the
mash to bring the temperature to 136 F (58 C). Do this
over the course of 5 minutes making sure to mix thoroughly.
Allow the mash to rest for 5 minutes at this temperature.
Remove about a quart of liquid from the mash and add to
kettle #2 and heat to 176 F (80 C). It will take about 3.5
quarts of water to raise the temperature to 136 F and you
will end up with a very soupy mash with plenty of excess
liquid. The liquid taken off should have the appearance of
milk. Once heated it will clear up and large particles of
hot break will form.

3.) Add more water at 212 F (100 C) to the mash over the
course of 10 minutes to bring the temperature to 150 F (65
C), again with constant mixing. It will take about 5
quarts of water to achieve this temperature. Allow the mash
to rest for 30 minutes at 150 F (65 C). At this point the
mash will be very soupy and the liquid much less milky in
appearance.

4.) Next remove 4 quarts of liquid from kettle #1 and add to
kettle #2. Continue to heat kettle #2 at 176 F (80 C).
The liquid removed from kettle #1 will be very cloudy but
not quite as milky as the liquid previously removed.

5.) Add more 212 F (100 C)water to kettle #1 to bring the
temperature to 162 F (72 C) and allow to remain at 162 F
for 20 minutes. Again it will take about 5 quarts of water
to reach the rest temperature. The mash should be very thin
and soupy with a great deal of small particulate matter in
the liquid portion of the mash.

6.) After the 20 minute rest the liquid in kettle #1 is run
off and brought to a boil in a 3rd kettle (#3). Enough of
the liquid in kettle #2, at 176 F, is added back to the
mash in kettle #1 to bring the mash to a temperature of ~167
F (75 C). The mash is allowed to rest at 167 F for 20
minutes. Any liquid left in kettle #2 can be added to the
previously collected run off in kettle #3. It will take
most all the liquid in kettle #2 (~1.25 gallons) to raise
the temp of the mash to 167 F.

7.) After 20 minutes the wort in kettle #1 is recirculated
to clarify it and the sparging with 185 F (85 C) water is
begun. Sparge until run off gravity has dropped to less
than 1.008 and boil it with the previous run off from kettle
#1. Boil the wort, now in kettle #3, until the volume is
reduced to ~ 5 gallons.

8.) As the wort begins to boil it is hopped with
approximately 4 ounces of aged hops as described in the
Hops section. With all the water additions and sparging you
will end up with about 9 gallons of wort. Total boiling
time to reduce this volume to 5 gallons will depend on what
kind of setup you have. At the beginning of the boil the
wort will be cloudy and full of large flocculent break
material. As the boil proceeds the wort should clarify as
the proteins continue to coagulated and the starch is
solubilized.

After boiling, the wort can be cooled using your method of
choice. This method of mashing does not seem to yield the
large amount of break that a typical all malt infusion mash
will yield. But as stated earlier your results may vary
depending on your equipment and technique.

Using this method yielded a wort with an OG of 1.040. This
is ~ 25 pts/lbs/gal. Thus the mash efficiency was not as
high as that obtained at Cantillon. The yield could
probably be improved by extending the times for the various
rest steps. Also it may be a good idea to heat the liquid
withdrawn from kettle #1 each time at a very slow rate. To
play it safe you may want to start out with a larger grain
bill based on the more conservative yield of 25 pts/lb of
grain.

In lambic production aged hops (2-3 years old), which have
lost all their bittering principals, are used. The rate of
hopping is very high, on the order of 400-600
grams/hectoliter or 3-4 ounces/5 gallons of wort. Aged hops
are used to avoid any bitterness that could affect the
acidic, pungent character of the beer. Typical varieties
used are of the low to medium alpha acid range, such as
Hallertauer, Tettnanger or Brewers Gold, though almost any
hop variety will do. You should avoid any of the high
alpha acid varieties, such as Chinook.

The homebrewer has a couple of options with respect to
obtaining and using aged hops. The brewer can buy hops and
leave them out at room temperature for a year or two to age
and lose bitterness. This requires planning and is not
convenient for the beginning lambic-style ale brewer.
Alternatively you or a friend may have some old hops that
you just could not part with but have never used. If these
are old enough they may serve the purpose. New hops can be
purchased and heated at low temperatures (<200 F) on a
cookie sheet for 4-5 hours. This procedure can also be
used for any hops you may have around and want to use.
Typically you want to heat the hops until all the aroma has
been driven off from the hops. Be aware that the smell may
not be one that others find pleasant. This author finds
that leaving hops in the Arizona summer sun for a week or
two seems to do a very good job of aging them. If you have
a total aversion to "ruining" perfectly good hops you may be
able to find hops at a reduced price at the end of the year
from your local homebrew shop or one of the many homebrew
mail order supply companies. Many times natural foods or
cooperative stores have hops in the herb department. These
are usually well aged and devoid of aroma with well
oxidized lupulin glands.

Whether you use whole or pellet hops does not seem to matter
as long as they are well aged. They can be used both alone
and together depending on what you have on hand. Crushing
the pellets into powder will help to enhance the oxidation
process. As the hops age they take on a very pale green to
yellow color and lose all aroma and the lupulin in whole
hops turns from yellow to orange-brown. During the aging
process the hops go through a stage of smelling rancid and
cheesy. This smell is unpleasant so it is best to leave
them in a well-ventilated area. You may want to put the
hops into a container with a fine mesh cover of some sort.
Then every once in a while you can mix the hops to enhance
oxidation.

The Belgian lambic brewers pump the boiled wort into shallow
coolships and allow the wort to cool naturally overnight in
the loft of the brewery. During this time period the
microflora of the brewery inoculate the wort. These
microorganisms along with those present in the fermentation
casks are what ferment the wort. If you are a brave soul
you can try your hand at spontaneous fermentation. This
approach seems to have met with limited success here in the
US among homebrewers. You may want to instead consider
open cooling with the addition of some pure cultures.
Alternatively, you can use a wort chiller of your favorite
type and then inoculate the cooled wort with the
appropriate cultures. You can also allow the wort to cool
overnight in the pot it was boiled in with the lid on. The
next day, siphon the clear wort off the trub into a
fermentation vessel. This method of cooling leads to large
amounts of DMS being formed in the wort due to the long slow
cooling. This will all be volatilized during the lengthy
fermentation process.

Traditionally after the wort is boiled it is allowed to cool
overnight and during this time it becomes infected with
various bacteria and yeast. These microorganisms come from
the brewery's own microenvironment and cause the wort to
ferment. A few individuals here in the US who have
followed this approach have gotten mixed results. More
often than not the resulting product is not a very close
approximation of what real a lambic is like. The majority
of lambic-style brewers prefer to use pure cultures to
inoculate their wort and ferment it. This gives them a bit
of control over the process but can still lead to largely
unpredictable results.

In spontaneously fermented lambic there is a succession of
growth of the various organisms as described in Lambic
and elsewhere (2, 10, 11, 12, 13). With pure culture
lambic one has numerous options regarding when and how to
add the various microorganism. These range from simply
adding all the cultures right after cooling, to adding each
organism separately at various times to mimic the
spontaneous fermentation growth cycle.

The whole process is further complicated by the decision of
what size inoculum to use. Should one try to duplicate the
traditional method where the initial number of cells/ml
wort is very small or should one use larger cell numbers to
ensure proper growth of these microorganisms? There is not
a simple answer to these questions and again many
techniques have been and need to be tried.

The Brettanomyces and Pediococcus are slow growing
microorganisms requiring special environmental conditions
to grow. Even under the best conditions traditional lambic
brewers have problems with some cask not fermenting properly
because the various organisms fail to thrive or grow too
much (14). (See Table "Variability of Fermentation") The
same thing can happen to those trying to make lambic-style
beers using pure cultures. If the environmental conditions
are not correct to start with or change too quickly, one or
more of the microorganisms may fail to grow or grow too
much and the resulting beer will lack the proper balance of
flavors. Of course there are not any definite answers as
to how to ensure the balanced growth of all the organisms
either.

A number of individuals have tried varying the starter size
as well as the addition schedule. Because lambic-style
ales take so long to develop the results so far are not
conclusive. One thing is known, and that is that you need
to have healthy cultures to start with and you need to
provide them with the proper environment with all the
necessary nutrients for growth. These goals can be achieved
by buying fresh cultures and using fresh extracts or
all-grain wort.

After you settle on an inoculation size and schedule there
are things you can do to achieve good growth of the various
yeast and bacteria in the wort. First of all you should
have a wort high in dextrins and unconverted starch. This
can be achieved by following the guidelines for wort
composition already described. Once you have cooled the
wort and it is inoculated you should allow it to remain in
one vessel for the entire fermentation process. This runs
counter to the typical practice of racking the beer to a
new container after primary fermentation is complete. By
not racking one does not remove the nutrient rich trub and
yeast which will undergo autolysis and provide nutrients
for the Brettanomyces yeast and Pediococcus bacteria. It
has been shown that once the Saccharomyces has done its
work the majority of B vitamins and amino acids have been
removed from the wort. Thus they act as a storage depot
for these nutrients which are later utilized by the other
microorganisms. (10)

Temperature control is not as crucial in lambic brewing as
with other styles of brewing, but one should still try to
avoid extreme temperatures and fluctuations. A temperature
that is too high or low may lead to too little or too much
growth of one or more of the various microorganisms. In
Belgium the temperature of the lambic cask rarely exceeds
77 F (25 C). Those who have been to Belgium have noted that
it is generally pretty cool most of the year. It has been
noted by one person that even in April the Boon Brewery was
cold. At the same time do not get too concerned about
the temperature since it may be hard to find an ideal
temperature environment for the 1-2 years it will be
fermenting. Overall you may be better off having your beer
too cold than too warm. It is speculated that cold
temperatures will help prevent over acidification of the
beer by the yeast and bacteria. At the same time this will
allow the other flavor characteristics to develop.

The truly dedicated brewer might consider having a
fermentation area with both heating and cooling. Then by
checking the weather reports for Brussels, Belgium each day
via the internet he could make temperature adjustments and
have his beer ferment at close to the same temperature as
the real thing.

When many people hear the word lambic they think of beer
flavored with fruit. Indeed most of the lambic sold in the
world today is of the type flavored with fruit in one form
or another. Traditionally cherries and raspberries were the
fruits of choice for use in the beer. Now one can find
lambic flavored with any number of fruits, including
banana. The more traditional brewers use real fruit in
their beers. Because this is both expensive and time
consuming many brewers choose to use fruit juices and/or
extracts. They also pasteurize the beer to stabilize the
fruit flavor. If they did not do this the Brettanomyces
and lactic bacteria would continue to ferment the various
sugars and dextrins and strip a great deal of the fruitiness
from the beer. The beer would not have that big fruit
flavor and aroma that has come to be associated with these
types of beers. Of course brewers who follow more
traditional techniques allow the fruit lambic to continue
fermentation in the bottle and this leads to a much drier,
less fruity product. Both styles of products are meant to
appeal to different drinkers.

As a homebrewer you have many options available to you. You
can use real whole fruit, fruit juice or fruit extracts or
a combination of these. From the information I have
gathered it appears that approximately 2 lb. of fruit/gallon
of beer is the amount used by a number of the lambic
brewers in Belgium. (See Table) You might think any fruit
would work, but this does not seem to be the case. You
really should use a strong flavored, tart fruit such as
sour cherry or raspberry or possibly blackberry. Less
intense fruits simply do not have the flavor to stand up to
the flavor of lambic- style beer and refermentation. Of
course there are exceptions to this general view. As
stated before some lambic brewers have gone to using almost
any fruit under the sun. They are able to get a highly
flavored product through the use of fruit juices and
syrups. They also add sugar to the beer, blend it with very
young lambic, force carbonate and pasteurize. Of course
then they end up with a product which many feel is very far
removed from traditional lambic.

In order to emulate what traditional lambic brewers do you
should use plenty of real fruit, of the best quality you
can find. Again based on the information gathered you will
want to let the lambic-style beer stay on the fruit for 3-6
months. The lambic- style ale you use should be at least
one year old and should show some potential of being a nice
beer without adding fruit. You are not going to make a silk
purse out of a sow's ear. You will not magically transform
a so-so gueuze-style lambic into a Cantillon Rose de
Gambrinus clone simply by adding fruit!

If you are going to add fruit to a beer rack the beer into a
larger vessels such as a 8 gallon plastic fermenter. This
will allow for the extra volume from the fruit as well as
provide head space as fermentation begins again. Let it
settle for a few days and then add the fruit. Add the
fruit carefully to avoid splashing and excess aeration of
the beer that may lead to acetobacter contamination and
growth. Alternatively you can rack the beer onto the
fruit. You can use fresh, frozen or canned fruit. You may
want to crush the fruit prior to addition. You may also
want to look into the fruit puree products that are
available. Refer to the supplier list (Oregon Fruit
Products). If the beer has developed the right mix of
Pediococcus and Brettanomyces then the conditions in the
beer should prevent growth of any unwelcome microorganisms
that may be present on the fruit. If you are going to use
fresh fruit make sure it is clean and free of molds and
dirt. Whether you crush the fruit or not will probably have
little effect as the various microorganisms should be able
to break it down after a few months.

After the beer has fermented on the fruit for the required
time rack the beer off the sediment into another vessel.
Then allow it to settle for a few weeks. Doing this lets
any large pieces of material that may have been racked over
to settle prior to bottling. When ready to bottle rack the
beer yet again and follow the bottling instructions for a
standard gueuze style beer.

When making lambic-style beer with fruit, it is difficult to
make a product that has good lambic-like qualities along
with balanced fruit flavor. As already stated many lambic
breweries now add fruit juice and pasteurize their products
and this gives them a sweet, fruity product. This is not
the kind of balance many of us are trying to achieve. For
many of us an ideal product is something like a Hanssens
Kriek or a Boon 1986 Mariage Parfait Framboise. These are
products with an assertive lambic quality and an excellent
fruit flavor, without being toothache sweet.

The question among homebrewers has always been how does one
make such a product? Of course you must start with a good
base lambic-style beer and use plenty of fruit. But even
then many of us have failed at our attempts to reach
Nirvana. Opinions vary on how one might achieve a good
fruit lambic-style beer. Do not use a beer that is
excessively acidic or "hard" as the base. If you need to,
blend it with some younger "softer" beer. Fruits like
raspberries contribute their own acidity to the beer.
Starting with a too acid beer just seems to make matters
worse. Ferment the beer with fruit at cool temperatures to
slow the growth of microorganisms yet allow the beer to
extract the flavors from the fruit. Cool being something
in the range of 60 F or less.

Based on some limited experimentation it seems that
sweetening a fruit beer that is overly sour helps bring out
the fruit. The problem is as long as there are live
microorganisms in the beer, they will ferment any sugar you
add to the beer either before or at bottling. It has been
suggested that one traditional lambic brewer adds
unfermentable sugar in the form of saccharin to the beer at
bottling so it retains its fruit character without being
pasteurized. Saccharin works well when added to lambic in
the glass to counter the acidity. If you choose to try
saccharin dissolve it in a small amount water and add it to
a glass of beer using an eyedropper to see how you like it.
Many people find a little saccharin goes a long way. And
some find the sweetness from saccharin too "chemical" in
nature. So test it before you decide to add it to 5
gallons of precious beer.

Another option is to sterile filter (0.2 micron) the beer
prior to the addition of fruit (whole, syrup or extract).
Allow the filtered beer to extract the fruit flavor, if
using whole fruit, for a few weeks. Fine the beer (if
using whole fruit) and then add sugar as needed and keg it
and/or counter pressure fill bottles. Using this method you
can achieve a product that has a balance of qualities you
enjoy. This is a far from traditional method. But after
all this is not Belgium and we are homebrewers so we can do
whatever we want. Please remember not to call it lambic.

Lambic-style beer can be fermented in a number of different
types of vessels. These can range from the standard food
grade plastic bucket to the finest quality European oak
cask. This section will give an overview of the various
containers one can use, including the possible advantages
and disadvantages each provide.

Let's start with the standard food grade high density
polyethylene (HDPE) container. These come in a variety of
sizes ranging from 5 gallon buckets up to drums of 15
gallons or more. These vessels have the advantage of being
inexpensive, light weight and practically unbreakable.
Also HDPE is somewhat permeable to oxygen and other gases.
This will provide for a slow and continuous gas exchange
during the lengthy fermentation and may aid in the growth
of the Brettanomyces and subsequent flavor development and
maturation. This is purely speculation based on the fact
that wood is also gas permeable and is the traditional
material used for lambic fermentation.

A possible disadvantage of HDPE is that it is a plastic and
being such is relatively soft and the surface can become
scratched. The scratches in the surface may then harbor
the wild yeast and bacteria from the fermentation process.
Some people feel that a plastic vessel once scratched can
never be adequately cleaned and sanitized. This theory has
never been proven but is considered part of homebrewing
folklore. Thus once a plastic vessel is used for making
lambic-style beers you may not want to use it for anything
else. As stated previously if a vessel is cleaned and
sanitized properly there is no reason to be concerned about
cross contamination.

Another type of plastic container commonly used by
homebrewers is the 5 gallon water bottle made of
polycarbonate (PC) plastic. PC is harder and more rigid
than HDPE and has about twice the gas permeability for both
oxygen and carbon dioxide(17). As mentioned for HDPE this
gas permeability may be of some advantage in the long term
aging of lambic-style beers. PC being a plastic has the
same perceived disadvantage as HDPE in that it can be
scratched and thus harbor bacteria and wild yeast. PC has
the advantage of being able to withstand boiling water
without melting unlike HDPE. This allows one to thoroughly
sanitize such a container since the whole vessel can be
heated to a temperature that will kill all bacteria and
yeast. This can be done using boiling water or an
autoclave. Remember, be very careful when pouring boiling
water into a container to avoid personal injury. PC is a
clear plastic that allows observation of the fermentation
process over time. This quality seems to be important for
those first time lambic- style ale brewers who worry whether
or not their beer is developing a pellicle or ropiness.

If one is careful to keep their plastic brewing vessels
clean to start with then the more drastic measures such as
boiling water or full strength bleach are not really
necessary. A good general guideline is to always clean a
vessel when you are done using it and then rinse it with a
sanitizer before putting it away. For further information
on cleaning and sanitizing materials please refer to these
references (18,19).

Glass is generally considered by homebrewers to be the best
material for fermenting beer for a number of reasons. It
is very inert, easily cleaned, inexpensive and does not
allow gas diffusion to occur. Also the clarity of glass
allows one to observe the fermentation process and the
various stages a lambic-style beer goes through over the
course of time. Glass carboys of five to 7 gallon capacity
will work just fine for producing lambic-style ales.
Remember glass is fragile and large pieces of broken glass
can inflict serious injury.

The impermeability of glass to gas diffusion is not likely
to be as important in lambic- style beer production as it is
for other types of beer. As stated before the traditional
oak cask is far from absolutely gas impermeable. Also the
fact that glass does not allow gas diffusion is made moot
by the fact that studies show that in a vessel the majority
of gas diffusion occurs through the closure and its sealing
surface (i.e. stopper or lid), not the vessel walls
(Personal Communication, Nalgene Technical Services).

Another material used by brewers is stainless steel, which
has the advantages of inertness, strength and ease of
cleaning. It is relatively expensive and completely
opaque. Even if one has an extra pot or keg to ferment in,
one must remember that it will have fermenting beer in it
for a year or more and thus not usable for other purposes.

The vessel used by traditional lambic brewers to ferment
their beer in is the European oak barrel. Oak barrels are
considered the ultimate vessel by many homebrewers making
lambic-style beers. The oak barrels used by lambic brewers
are generally used wine barrels of European origin. They
have had the majority of tannins and other wood related
compounds leached out of them by wine fermentation. The
traditional lambic brewer has various barrels, many of which
are quite old, with the size usually being 600 liters or
so.

The advantage of an oak cask over other vessels is that it
provides a microenvironment where the various yeast and
bacteria can grow. This is due to the porous nature of the
wood, which provides nooks and crannies for the
microorganisms to inhabit.(20) The permeability allows the
slow diffusion of air into the fermenting wort and this may
further aid the growth of the microorganisms as well as
flavor development. After a cask has been used for a number
of batches it will become, one hopes, infected with the
right microflora further aiding in the production of a more
authentic product.

It also seems that as a cask is used for many years the
various flavors from previous batches of beer as well as
those from the yeast and bacteria build up in the wood and
further add to the complex flavor profile of each successive
fermentation. It is felt by some that even old oak adds a
certain minor astringent note to the lambic from the
remaining tannins that are slowly leached from the wood.

The homebrewer has to consider a number of things before
obtaining an oak barrel. One has to consider the size, the
type of oak (American or European), where to put it and
whether to get a new or used one. First let's look at the
type of oak barrel to buy. Regardless of whether you
choose to buy a barrel made of American or European oak,
make sure it is a wine barrel that is uncoated. Do not buy
a whiskey barrel as they are charred on the inside and
really only meant for making whiskey. Do you really want
that burnt wood flavor in your lambic-style beer? Your best
bet is to buy the barrel from a cooperage rather than
through a homebrew supplier. That way you can get
specifically what you want and also save some money.

It is generally felt that European oak is superior to
American oak. This is based on the fact that American oak
trees and European oak trees are different species (21).
This leads to them having different profiles of the various
compounds that are extracted during the fermentation
process. The grain structure and thus porosity of the two
species is also different. It is felt that American oak is
too "oaky" as compared to European oak. There is some
truth to this, but in the past few years things have
changed (22). Part of the problem with too much "oakiness"
in American barrels has to do with the way the wood is
dried and aged. European cooperages have traditionally
aged their wood for at least 2 years before it is used to
make barrels. During this drying and aging process many of
the oaky compounds are volatilized from the wood.

American cooperages on the other hand quite often oven dry
the wood in a matter of days and then used it to make
barrels. This leads to an over abundance of oak character
left in the wood. Some cooperages still use this method for
their less expensive barrels. Others have started to
follow European practice and are aging their wood for
extended periods. Unfortunately most of the cooperages in
America that age their oak dont make barrels in any size
less than 200 L. If you are looking for a barrel of 5-15
gallons you will probably have to do some calling around to
see if you can find a barrel in stock made of aged wood.
Small barrels are not kept in stock by many cooperages
because demand is relatively small. Also it is no surprise
that many of the cooperages are in California due to the
large wine industry there.

Another factor to consider is the cost of European vs.
American oak. The majority of European oak barrels come
out of France and currently the franc is pretty weak. An
investigation of prices for barrels revealed that most
European barrels cost almost twice as much as equivalent
American barrels. If cost is no object and you are in the
market for a new wine barrel then of course go ahead and buy
a barrel of European origin.

If you choose to buy an American barrel make sure it is a
wine barrel. Again try to find one that is made from air
dried wood, preferably of a year old or more. Also get the
barrel with a medium "toast". This is a process where the
insides of the staves of the barrels have been lightly
browned but not charred as with a whiskey barrel. This is
done to barrels that are destined for red wine production
since it further reduces the tannins and oakiness of the
wood. Since a barrel is a major investment ask to speak to
a cooper about how to prepare the barrel. Ask what will be
done if the barrel fails to hold water when you fill it.
Will they exchange it for a new one? Most cooperages have
people on staff willing to discuss how to prepare a barrel
and are willing to provide an exchange for a leaky barrel.
If you buy a barrel from reputable cooperage leaking should
not be a problem anyway. Barrels come in a range of sizes
starting at around 3 gallons and going up to 50 gallons or
more. Typically though, European barrels do not come in
sizes smaller than 25 liters.

If you choose to buy a barrel remember that it is going to
have liquid in it for a year or more. It will need to be
in an environment that does not freeze or exceed 80 F (27
C) as these are the general extremes in temperature
encountered in Belgium. A barrel full of beer is going to
weigh 8.3 lb./gallon of liquid plus the weight of the
barrel. If you choose to buy a 10 gallon or larger cask
think about the logistics of filling and storing it ahead
of time. Due to the weight you may need a hoist or a few
strong friends to lift it. Also be sure you have the
brewing capacity to fill the barrel. It is not a good idea
to partially fill the barrel. This may lead to drying of the
staves and leakage.

The price of a barrel does not increase linearly with size.
Typically a 10 gallon one is only about $20-30 more than a
5 gallon size. This holds true whether you buy American or
European. Most of the cooperages selling American oak
barrels designate the size by the gallon capacity whereas
the dealers of European barrels designate size by the
liter. This is just another point to consider when
investigating a purchase.

Another source of barrels is previously used ones. Many
wineries in the US use 200 or 225 Liter European barrels
and you can pick them up for around $50 used. This
requires you live near a winery and that you have the
brewing capacity to fill it and the storage space. Many
wineries only use the barrels for 3-4 years before selling
them. The trend toward using barrels for a shorter time has
come about due to the decreasing use of sulfites and the
increased risk of Brettanomyces infection this can bring
about. Thus you can get a barrel in really good shape for
an excellent price. Unfortunately finding used barrels of
smaller sizes is not so easy. Wineries and cooperages that
deal in used barrels usually do not have anything other than
200- 225L sizes. It seems wineries do use the smaller sizes
to keep wine in that is used to make up the ullage in the
big casks. But they use these small casks until they are
ready to be used as fire wood. So if you find someone with
a used 5 or 10 gallon barrel for sale that is in good shape
consider yourself lucky. Another source of used barrels
maybe home wine makers who might be getting rid of a used
cask. Finally note there is a company that is
reconditioning the larger used barrels and downsizing them
to 30 gallons. (See Barrel Supplier List)

Some people warn that any beer made in an American Oak
barrel will taste like an oak branch. They also feel that
it will take numerous batches of beer to extract all the
oakiness from the wood. You will have to make a personal
decision regarding American vs. European Oak. Regardless
of what you buy you want the majority of the oak character
removed from it prior to using it. The quality of a
European barrel is not necessarily twice as good as an
American one either. Any barrel, if well cared for will
last for decades. To reduce the chances of oak beer you
will want to buy either a used barrel or a new one that is
made from air dried wood with a medium toast interior.

Regardless of the source any new barrel is going to have a
certain degree of oak character that will be imparted to
the beer. This is particularly true in the making of
lambic-style beer, where the wort stays in the barrel for a
long period of time. During this time period a great
amount of chemical compounds can be extracted out of the
wood. So it is suggested that you chemically strip the
barrel. When you first get the barrel you will need to
swell it with water to make it liquid tight. It is at this
stage when you find out if the barrel is of good quality or
not. At first you will need to top up the barrel daily as
the wood swells and absorbs water. It may leak some at
first, but should stop after 3-5 days. Once a good quality
barrel has been swelled it should show no further signs of
leakage unless damaged.

To maximize the amount of oak compounds leached out of the
wood change the water in the barrel every three days for
two weeks. This also ensures no mold will grow in it. If
you live in an area that has high humidity you may want to
add metabisulfite from the start at the rate of 200 PPM.
After two weeks of soaking start the chemical stripping
process to really remove the oakiness. This is done by
adding sodium carbonate (washing soda) to the cask at the
rate of 1/2 ounce/gallon and letting it soak for a week.
Then drain the cask, rinse it well and repeat the process.
To maximize the extraction repeat this process for 4 to 6
weeks. At this point the water in the barrel should be
clear when drained as compared to the tan liquid when you
start the process. Next neutralize any residual sodium
carbonate by adding citric acid to the cask full of water
to drop the pH to 3 and let it set for a few days. Then
rinse it well and fill it with metabisulfite solution to
inhibit mold growth until you can brew and fill it with
wort.

Following this stripping procedure can help you reduce the
chances of having multiple batches of oaky beer. If you
get the right barrel and are careful to strip it thoroughly
there is no reason not to use a barrel of American origin.
Besides, even a European barrel will need to be stripped to
some extent to reduce the oakiness that is present in any
new unused barrel.

So now you have a barrel and it has been full of beer for a
year or two and you want to bottle the beer. What do you
do with the barrel once it is empty? First you should
never leave a barrel that has held liquid empty for any
period of time as it will dry out and shrink. This may
lead to leakage that will not ever stop. Sometimes a leak
can be stopped by hammering the steel bands of the barrel
closer to the center. You will be better off if this can
be avoided.

Since lambic-style beer takes so long to ferment and age,
when you bottle is not very critical. You will be better
off if you coordinate when you will empty the cask for
bottling to a time when you can brew a new batch to fill the
cask up again immediately. For example, the day you are
brewing you can transfer the contents of the barrel to a
carboy(s) or other holding vessel leaving as much of the
lees behind as possible. This will allow the beer a chance
to settle until you are ready to bottle anyway. Then you
can rinse the cask out with water and have it all ready to
fill when your wort is cooled. This way there is no chance
of the cask drying out and all the microflora in the wood
remain intact and happy. If you must empty the barrel and
cannot fill it immediately, rinse it with water and burn a
sulfur candle in it and bung it up tightly or fill it with
metabisulfite solution. Then when you have time to brew
rinse the cask well and fill it with wort.

A barrel is a major investment and can be ruined if it gets
moldy on the inside. Thus it is important to keep it
filled up close to the top at all times. This requires
making up the ullage at regular intervals depending on the
dryness of where you live. Also as previously stated, when
there is not beer in the cask keep it filled with
metabisulfite solution. Do not use bleach or iodophor as
these would likely taint the wood and kill all microflora
present in the wood.

The outside of the cask also requires regular attention.
Again depending on where you live the outer surface may
develop mold over time. You can spray the outside of the
cask with metabisulfite at regular intervals or whenever you
see signs of mold developing. Some people use a 200 PPM
bleach solution or 25 PPM iodophor. These are probably OK
to use as long as you do not saturate the wood with them.
Others favor applying linseed oil to the outside of the
cask. The important thing is to keep an eye on your
barrels and treat mold and mildew infections when they
develop. This is all part of taking care of a barrel so
that it will last for years. It would be a shame to have a
cask well infected with Brettanomyces and Pediococcus,
ruined by mold.

Oak Chips

The contribution of the oak from a cask to the
flavor of lambic is considered to be minimal based on
discussion with various individuals. This is due to the
fact that the casks used are many times decades old and
were previously used for wine fermentation. Thus they have
had the vast majority of tannins and phenolic compounds
leached out of them. This said, it is still felt by some
that the oak may add some astringent quality to the lambic.
If you feel that using oak may help contribute complexity
to the flavor of your lambic-style ale but do not want to
deal with a cask then you might want to consider using oak
chips. The are usually available from homebrew shops or
can be specially ordered. It is suggested you use toasted
chips and that you soak them in a couple of changes of
boiling water prior to using them in the fermenter. This
will help remove the majority of the oak flavor compounds
from the wood. You do not want beer that tastes like an
oaky Chardonnay. Preliminary experiments indicate that
after the chips have been exposed to lambic-style ale the
microorganism do invade the pores of the wood. This was
shown by taking the "infected" chips and washing them
thoroughly with sterile water. The chips were then added
to sterile wort from which Brettanomyces and Pediococcus
could then be recovered. Researchers have shown that the
microorganisms do indeed invade the pores of the wood (20).
This is another area wide open for experimentation.

Homebrewers and brewers in general are concerned with
sanitation and about bringing wild yeast and bacteria into
their breweries whether by accident or deliberately. Such
concerns apply more to the professional rather than amateur
brewer. The homebrewer can easily take all his equipment
apart and thoroughly clean and sanitize it. The
professional does not have this luxury. Carboys, buckets,
hoses and other equipment can all be exposed to the
appropriate cleaners and sanitizers to eliminate any wild
yeast and bacteria. This writer brews all his beers using
HDPE and PC containers and has used the same containers to
brew lambic- style as well as other beers for the last 3 or
so years. Cross contamination has not been a problem at
all. It is important to clean and sanitize all equipment
thoroughly before and after each use. Make sure all
equipment is free from any dirt and grime and use an
appropriate sanitizer. After a container has had beer in it
for a year it is important to clean it well. Automatic
dishwashing detergent works well for this task since it
contains TSP as well as sodium hypochlorite. Thus it does a
preliminary job of sanitizing the container. You can then
soak the container overnight in your favorite sanitizer
and then rinse it out the next day. By following good
cleaning and sanitation practices you should not have to
worry about cross contamination. If you are concerned
about contamination you may want to have a dedicated set of
equipment for lambic-style beer brewing. For a more
thorough discussion of cleaning and sanitation you may want
to consult some additional references (18,19).

During the first month of the spontaneous fermentation of
lambic beer the dominate bacteria consists of
enterobacteria. These bacteria grow very rapidly and effect
the growth of subsequent yeast and bacteria. They also
effect the flavor of the beer via the various metabolic
byproducts they produce.

The enterobacteria that have been found to be present in
lambic beer include Enterobacter cloacea, Klebsiella
pneumoniae, Escherichia coli, Hafnia alvei, Enterobacter
aerogenes and Citrobacter freundii. These are gram-negative
straight rods which are motile with the exception of
Klebsiella. There can also be non-motile variants of the
other species. They all are able to ferment glucose with
some producing gas while others do not. Most of them grow
quite well in the presence of air and are also able to
ferment lactose. These bacteria follow either a butanediol
fermentation pathway or a mixed acid pathway. This leads to
large amounts of lactic (~1500 ppm), acetic (~600 ppm) and
succinic (~275 ppm) acids along with 2,3 butanediol (~2000
ppm) being formed in the first month of the fermentation
(10, 23). They can reach levels of 1 X 108 cells /ml
during the first 30-40 days of the fermentation. After
this period the decrease in pH and the increase in alcohol
caused by yeasts of the Saccharomyces species causes them to
die off.

The various by products from the growth of the
enterobacteria can lead to various flavors described as
celery-like, parsnip-like, mushroom-like, smoky or mouldy
(10). These flavors are not removed by the fermentation
process. The various acid products described previously
also have an impact on the beer flavor contributing to the
acidic taste of the final product. In fact the majority of
acetic acid found in lambic beer originates in the first
month and is the byproduct of enterobacterial growth.

Typically enteric bacteria are considered pathogenic
(disease-causing) in humans. They are often considered the
cause of various forms of food poisoning. This is indeed
the case, with Salmonella being cause of the vast majority
of cases (24). The enteric bacteria found in lambic are
generally not considered pathogenic in people other than
those who have immune systems that have been compromised in
some way (i.e AIDS or immunosuppresive chemotherapy).

Research has shown that the kitchens of many peoples homes
harbor more enteric bacteria than their bathrooms. (24)
These bacteria include all those found in lambic along with
Salmonella. Meats, vegetables and kitchen sponges or wash
cloths have all been found to be highly contaminated, with
the later having particularly high bacterial counts. This
makes the kitchen an ideal environment for allowing the
introduction of enteric bacteria into ones wort.

Discussions among homebrewers about making lambic-style
beers have also avoided the subject of enteric bacteria.
This has been due to the fear of food poisoning and the
associated side effects. Again research would indicate that
anyone who brews in their kitchen does indeed end up with
some amount of enteric bacteria in there beer. The growth
of the brewing yeast and the subsequent reduction in pH and
increase in alcohol kill the bacteria off before they can
cause off flavors or other problems in the majority of
cases.

It can be argued that without enteric bacterial growth and
the subsequent depletion of glucose and production of
metabolic byproducts lambic would probably not have the
depth of flavor and complexity that it does. Because
homebrewers have been "afraid" of enteric bacteria they are
missing an integral part of the production process.
Studies indicate that the enteric bacteria have a profound
effect on the subsequent growth and flavor development in
real lambic. In order to achieve the same flavor profile
it would seem important to have this initial growth of these
bacteria.

In order to allow the wort to become infected with enteric
bacteria a reasonable approach would be to leave the
fermenter open near a kitchen sink for an hour or two after
the wort has cooled. Then the brewer should wait an
additional 24 hours before adding any yeast. This will
allow the enteric bacteria to gain a foothold and begin to
grow and multiply to a level that allows them to produce a
significant amount of metabolic byproducts and deplete the
glucose. After 24 hours the addition of a small amount of
yeast will ultimately lead to the enteric bacteria being
killed off. Again because the yeast will produce alcohol
and lower the pH of the wort to a level at which the
bacteria can no longer survive.

Brettanomyces is considered one of the major yeasts
responsible for the flavor characteristics of lambic.
Typically the species most homebrewers use are either
Brettanomyces bruxellensis or lambicus. These yeast have
cell shapes that are usually ellipsoidal and can also be
cylindrical or elongated. They frequently form chains as
they grow also. These cells quite often form
pseudomycelium and grow as filamentous branched cells. (25,
26) This gives the cells the ability to float and form a
pellicle on the beer.

Brettanomyces have the ability to form acetic acid from
glucose under aerobic conditions. Thus when they grow on
calcium carbonate agar there is a visible zone of clearing
around the colonies. They demonstrate a negative Pasteur
effect. That is they demonstrate a higher production of
alcohol under aerobic conditions as opposed Saccharomyces
which show decreased alcohol production under aerobic
conditions (27). Brettanomyces also have cellular
dextrinases that allow them to utilize dextrose polymers
larger than the typical trisaccharides that can be utilized
by Saccharomyces. A culture of Brettanomyces has a
characteristic acetic, earthy, horsey aroma. These yeast
grow much more slowly than do Saccharomyces brewing
strains. Also they are resistant to cycloheximide unlike
most normal brewing yeasts. Brewers classify Brettanomyces
as "wild" yeast and typically do all they can to avoid
them. In normal brewing these yeasts will lead to various
off flavors described as phenolic, smoky and goaty. In
lambic beer these are desired characteristics.

Another aspect of Brettanomyces is their ability to
enzymatically catalyze the formation of esters from the
corresponding alcohol and acid. Thus ethyl alcohol and
acetic acid can be combined to from ethyl acetate and lactic
acid and ethanol can be combined to form ethyl lactate.
These are two of the primary esters found in lambic beer
(28, 29).

Of the lactic acid bacteria found after about three months
of fermentation, Pediococcus damnosus is the dominant one
in traditional lambic brewing. It is a spherical,
tetrad-forming, gram positive bacteria. Pediococcus is
described as a homofermentative bacteria because it
ferments glucose to lactic acid without the production of
carbon dioxide. As the Pediococcus grows the concentration
of lactic acid increases and can reach levels of 5000 PPM
or more in the lambic. This increase in acid is a slow and
progressive occurrence over a number of months.
Pediococcus is a very fastidious organism, meaning it grows
slowly and has complex nutritional requirements. Because
of this fact and the environmental conditions, the
concentration of cells is never very high, being only 1 X
106 cells/ml or less. Of course this is in reference to
spontaneously fermented lambic; cells numbers may be higher
in an artificially inoculated wort. The lactic acid as well
as diacetyl and acetoin that the Pediococcus produce
contributes to the complex flavor and aroma of lambic, with
the acid making the largest contribution. The levels of
vicinal diketones (diacetyl and acetoin) have been found to
be at or below taste threshold levels.(13)

To brew lambic-style beer it is advantageous to know the
basics of yeast culturing. It is a further help to know
how to culture the various organisms specifically involved
in lambic fermentation. For the purposes of this article
the discussion will focus on the culturing of what are
considered by many to be the primary players in the
fermentation process. Besides Saccharomyces these include
species of Brettanomyces yeast and Pediococcus damnosus
bacteria.

Any type of Saccharomyces can be used for the primary
fermentation of a lambic- style beer, since it will
contribute little if anything to the overall flavor profile
of the finished product. One can find any number of
articles and books on how to culture these yeast and
maintain them in the home brewery. (25, 26, 30, 31, 32)

It is the other organisms involved which are more difficult
to culture and maintain without some experience and
knowledge of how they grow. The yeast of the Brettanomyces
species bruxellensis and lambicus and the bacteria
Pediococcus damnosus are microorganisms that require very
specialized nutrients and environmental conditions. It
should be noted that unless you are going to brew
lambic-style beers more than once or twice a year you may be
better off buying new cultures each time rather than trying
to maintain them in a home environment. If you do feel the
need to maintain the cultures at home then you should become
very familiar with the culturing of normal brewing yeast
first.

Both Brettanomyces and Pediococcus produce acids as normal
metabolic by- products and because of this they need to be
maintained on media which can help neutralize it.
Otherwise, the acid will lead to a large drop in pH and the
organisms will die. The most readily available food grade
acid neutralizing agent is calcium carbonate (CaCO3), also
called precipitated chalk. A concentration of 2% (2 g/100
ml) in the growth media or agar will provide adequate
buffering capacity. Calcium carbonate is essentially
insoluble though and this can present problems if it is used
in making wort agar. To prevent the CaCO3 from falling out
of solution before the agar solidifies, cool the wort-agar
solution to 113-122 F (45-50 C), with constant swirling,
prior to pouring it into the tubes or dishes. When CaCO3 is
used in liquid media one can gently swirl the media with
the culture growing in it once or twice a day to help
prevent any stratification of the acid in the solution and
aid the neutralization of it with the CaCO3. As the lambic
organisms grow in the liquid media the acid produced will
react with the CaCO3 causing it to be solubilized over time.
Even when a culture reaches maximum confluence there may
still be some CaCO3 unneutralized, but this is not anything
to worry about as the acid produced by the growth in the
main wort will dissolve it in time.

The Brettanomyces yeast can be grown on wort agar which
incorporates 2% CaCO3 as noted previously. The wort itself
should be of a gravity of approximately 1.040 and
preferably made from an all grain wort due to the possible
lack of nutrients in malt extract (5,6). Due to the
fastidious nature and acid production by Brettanomyces they
need to be transferred to new slant more often than do
Saccharomyces. It is recommended they be transferred to new
slants at least every 2 months. Longer intervals between
transfers may lead to cultures which are no longer viable.

Because of this frequent manipulation there is a greater
chance the yeasts themselves may become contaminated with
other yeast, mold or bacteria. Thus your sterile culture
technique needs to be very good and you need to pay
attention to details. If your culture does become
contaminated you can prepare a dilute suspension of the
yeast and streak it out on a petri dish which has wort agar
with 2% CaCO3 and also incorporates 10 ug/ml cycloheximide.
(Appropriate cautions inserted) As the colonies grow watch
for a zone of clearing around the individual colonies.
Agar prepared with calcium carbonate will be opaque and
white in color and as the Brettanomyces grow the acid they
produce will dissolve the calcium carbonate and create the
zone of clearing. Generally only non-Saccharomyces yeast
will grow on media with cycloheximide in it and those that
do grow and have zones of clearing around them are likely
to be Brettanomyces. You can then pick the colonies off
and re-culture them on cycloheximide-free media. This is by
no means a definite technique for the isolation and
characterization of Brettanomyces. Yeast such as Kloeckera
are also acid producers that will grow on cycloheximide
agar. If you have doubts at all then you may be better off
buying new cultures and/or locating a microbiologist who
will work for homebrew. The only absolute way to
characterize a culture is through extensive fermentation,
assimilation and morphological testing, dont believe it if
someone tells you otherwise.

Pediococcus is more difficult to grow and maintain than is
Brettanomyces due to its more complex nutritional and
environmental requirements. Pediococcus grows best in
liquid rather than solid media and this increases the
chances for unseen contamination. Unless you have access
to a 1000X power microscope and have culturing experience,
it is recommended that you do not try to maintain this
bacteria at home for any length of time. MRS (deMan,
Rogosa and Sharpe) broth is the preferred media for growing
and maintaining Pediococcus over long periods. It is a
defined media that is rather expensive but provides the
necessary nutrients and buffers for optimal growth over
extended periods. Prepare the media as indicated on the
package. Sometimes bacteria can lose their hop resistance
if grown in unhopped media for extended periods. Thus if
you are going to try to keep cultures going over a period
of time it is suggested you add iso-alpha acids to the media
using some type of hop extract. Use of whole or pellet hops
leads to particulate matter which causes the media to
become cloudy and less than ideal for visual monitoring of
growth. A suggested level is in the 15-25 IBU range. A
minimum suggested passage interval is every month. Allow
the culture to grow for a week at room temperature and then
it can be stored at 4 C. Another method for storing
Pediococcus is the use of stab cultures. MRS media is
prepared using 1.5 % agar and put into tubes. The tubes of
solidified media are inoculated by using a needle or
inoculation loop to stab the bacteria into it. The
bacterium is allowed to grow at room temperature for a week
or so until signs of growth can be seen. Then the tubes
can be stored at 4 C. Whether you use liquid or stab
cultures you need to keep the tube caps screwed down tight
to limit air diffusion into the cultures and prevent
desiccation. There is no need to worry about pressure
buildup since Pediococccus are not gas producers. The same
caveats apply to bacteria culturing as for lambic yeasts:
you need the proper equipment and good technique.

If you are going to get serious about culturing
microorganisms used for lambic-style beers then you might
consider buying or building a laminar flow hood of some
type. This will allow you to work in a nearly sterile
environment. Fungi Perfecti is one of several companies
that sell them or you can build your own. (33)

Because lambic-style beers are not widely brewed the
Brettanomyces yeast and Pediococcus bacteria are not always
available on the shelf at your neighborhood homebrew shop.
The other reason for limited availability is that these
cultures do not maintain viability for as long a period of
time as do more traditional brewing yeast. Both the
Brettanomyces and Pediococcus are acid producing organisms
and this causes them to literally kill themselves off when
stored for extended periods. Also the organisms are
extremely fastidious, meaning they have complex nutritional
and environmental requirements and cannot be maintained in
static storage for long periods.

The following is a list of suppliers both retail and
wholesale who are known to carry the cultures and/or the
culturing equipment and supplies needed to grow and
maintain these organisms. No endorsement is made for any
particular company.

e-mail gummitch@teleport.com
They carry the Wyeast 3278B and also a complete line of
laboratory supplies, culturing equipment and growth media.

Brewer's Resource
409 Calle San Pablo #104
Camarillo, CA 93012
1 (800) 827-3983
They carry both Brettanomyces and
Pediococcus and a line of culturing equipment and other
supplies for the homebrewer wanting to do their own
culturing.

Difco Laboratories
P.O. Box 331058
Detroit, Michigan 48232
1 (800) 521-0851
They do not sell direct, but only through
distributors. When you call request a catalog and the name
of your local distributor. They are an excellent source of
media and chemicals needed for the growth and isolation of
both yeast and bacteria of all types. I have had no
problems buying from my local distributor. Be prepared for
sticker shock when you see the catalog though.

Fungi Perfecti
P.O. Box 7634
Olympia, WA 98507
(206) 426-9292 WWW: http://www.halcyon.com/mycomed/catalog.html
Fungi Perfecti is a company that sells supplies and
equipment for culturing mushrooms. Because cultivation of
mushrooms requires sterile technique they sell a wide
variety of laboratory supplies and equipment that are also
useful to the homebrewer who does his or her own yeast
culture. Note their catalog is not free but the price is
deductible from the first order. They also have a page on
the WWW.

HeadStart Brewing Cultures
256 Cherokee Rdg.
Athens, GA 30606
(706) 548-7051
This company has Brettanomyces strains of various origins as
well as Pediococcus and other yeast and bacteria for
brewing non-traditional beers. They also have various
culturing supplies and media.

U-Brew
319 1/2 Millburn Ave.
Millburn, NJ 07041
(201) 376-0973
This is a homebrew shop that carries bottle caps and a
capper that work with European champagne and lambic
bottles.

Wyeast Labs and G.W. Kent sell wholesale only, but you can
obtain their products through your local homebrew supplier.
Wyeast sells a yeast that carries the designation #3278B
(previously 3278 Brettanomyces Bruxellensis). G.W. Kent
sells a strain of Brettanomyces and a strain of Pediococcus
through their Yeast Lab division.

Regarding the Wyeast 3278B and its composition, the company
sent the following letter to retailers:

This name change reflects the fact that this yeast is a
blend of yeasts and not 100% of one particular strain. The
product has not changed; as many of you know, certain
Belgian beer styles require more than one yeast to make a
good beer. For several years we have produced this blend,
because using 100% of one yeast would make an unpalatable
beer. This item will remain available with a modified label
as indicated.

We are sorry if this has caused any inconvenience. Please
call or write use if you have any questions or comments.

Sincerely, Dave Logsdon.

Barrel Supplier List Note: The first four suppliers on this
list carry barrels in smaller sizes (i.e., 5-7 gallons or
the metric equivalent) The other suppliers may or may not
have barrels smaller than 200 liters. Napa Fermentations
carries both European and American Oak barrels.
Independent Stave makes only American oak barrels. Both
Demptos and Seguin Moreau carry only European oak barrels.
This information is believed to be correct at the time of
this writing. Typically a European oak barrel will cost
twice as much as an American equivalent and the price you
pay will also depend on the current exchange rate for
foreign currency.

You will find that the cost of a barrel does not increase in
a linear fashion with size (i.e. a 10 gallon barrels does
not cost twice as much as a 5 gallon) So it pays to shop
around and decide what your needs are really going to be.

If you are considering making really large batches you can
pick up used 200-225 L barrels from wineries for around
$50. Smaller sizes are nearly impossible to find used
because wineries use them to hold wine for topping up the
big casks and use them until they are ready to be used as
fire wood.

All beers were from the same brewery. The "soft" and "hard"
beers were both from the same batch of wort and were 9
months old. The "ropy" beer was 6 months old. Reference
(14).

Figure on Page 75 in Lambic A discussion

This figure illustrates a number of important points with
regard to the production of lambic beer. First of all it
should be pointed out that the data represented here all
came from one lambic brewery and was collected 20 years ago.
It does not necessarily represent the fermentation process
in all lambic breweries in Belgium. But it does provide
some very good insight into what occurs in lambic over time.
Remember that all the organisms that are present in lambic
are introduced when the wort is cooled and transferred to
the casks. No pure culture additions are made at anytime.

During the cooling process microorganisms enter the wort
from the brewery environment. The view that they are blown
in on the night air and that the Senne Valley is the only
place in the world where a spontaneously fermented beer like
lambic can be produced is a somewhat silly romantic notion
that has been shown to be basically untrue. Dr Verachtert
has written "...the special microclimate of the river
Zenne accounts for the special mysterious microbial flora
necessary for lambic brewing." Translated into scientific
terms this means that the brewery environment has become a
source of appropriate micro-organisms and that lambic can be
brewed at other locations provided the brewer is prepared
to enter a long period of trial and error. All the yeast
and bacteria are already in the brewery and fall into the
wort more than likely attached to dust and dirt particles.
Insects, particularly flies and the occasional bird are
also responsible for "inoculation" of the wort. Another
source of microorganism is the pipes used to transfer the
wort from the coolship to the mixing tank and from the tank
to the fermentation casks. And finally the cask themselves
harbor bacteria and yeast since they are never really
sterilized between uses. Typically the only treatment
barrels get is a good hot water rinse, a scrubbing with
chains and then a sulfur candle is burned in them to inhibit
molds.

By the second or third day the fermentation process is well
underway with foam being produced by the metabolic activity
of the enteric bacteria. These bacteria as stated before
are primarily responsible for the acetic acid in lambic. As
you can see the acetic acid reaches a constant level in a
few weeks, showing no further increases. At the same time
yeast of the species Kloeckera apiculata begin to grow as
well. The combined metabolic activity of these
microorganisms consumes most of the available glucose and
free amino acids.

After about two weeks the Saccharomyces species begin to
overgrow the wort. Their growth seems to be delayed
partially because the enteric bacteria and Kloeckera
apiculata have consumed most of the readily available
nutrients. The enteric bacteria further hinder the growth
of the Saccharomyces through some as yet unknown mechanism.
Once the Saccharomyces begin to grow they produce ethanol
and lower the pH of the wort and this leads to the enteric
bacteria and Kloeckera being killed off. The Saccharomyces
are responsible for the main alcoholic fermentation. They
dominate for about 3-4 months and then their numbers begin
to slowly decline. This decline is primarily due to the
increase in acidity brought on by the growth of lactic acid
bacteria and Brettanomyces yeasts. The Saccharomyces seem
not to be able to survive the combination of ethanol, acetic
and lactic acids.

At three to four months lactic acid bacteria of the species
Pediococcus damnosus become the dominant microorganism in
the wort. This increase in growth coincides with the
increase in temperature that occurs at the onset of spring
and summer. The increase in temperature is important, for
otherwise the bacteria will not proliferate and the
subsequent acid production will not occur. This
proliferation of the lactic bacteria can be seen occurring
with each summer the wort is in the cask.

At times the lactic bacteria reach very high levels and the
wort will become "ropy". This is due to exopolysaccharides
that the bacteria produce and causes the wort to become
viscous and stringy. Though it is visually unappealing it
is completely harmless. It seems that subsequent growth of
Brettanomyces leads to the slime being broken down and
disappearing. The lactic bacteria are an integral part of
the lambic fermentation leading to the large amounts of
lactic acid found in the beer.

After about seven to eight month the lactic acid bacteria
have declined and yeast of the species Brettanomyces begin
to take over. For the remainder of the fermentation period
these are the dominant yeast found in the beer. They have
the ability to hydrolyze dextrins and thus breakdown the
remaining polysaccharides in the wort.

The Brettanomyces yeast are responsible for many of the
chemicals found in the beer and the characteristic flavors
and aromas they lead to. As already discussed these
include ethyl lactate, ethyl acetate and the various organic
acids such as caprylic, capric and caproic acid along with
a number of other chemical compounds. It is the
combination of these many compounds that add to the overall
flavor complexity of a fine lambic.

As with the lactic bacteria the Brettanomyces yeast grow
very slowly and never reach very high numbers. Also due to
their ability to form branching structures they can float
and form a pellicle on the top of the fermenting beer. It
is felt that this film helps protect the beer from
subsequent oxidation over the long fermentation period.

An important point indicated by the graph is that by 12
months the beer has come close to being at steady state.
That is the levels of alcohol, acetic and lactic acid, and
ethyl acetate have reached constant levels. After the first
year what then occurs is that various other compounds are
either produced or converted and any remaining
polysaccharides are broken down. This a very slow process
due to the fastidious nature of the microorganisms. The
process is further inhibited by the unfavorable
environmental conditions of very low pH and high alcohol
that inhibit the enzymes of the yeast and bacteria. Once
the beer is put into the bottle these changes and chemical
reactions continue to occur but again at a very slow rate.
This is why lambic beer takes so long to ferment and
develop in the bottle. The take home message is to be
patient and not try to rush things.

Making lambic-style ale can be as easy as boiling up some
extract and throwing in some cultures. Or it can be done
using very traditional techniques and methods. The main
factor is that regardless of what you do the beer will take
time to ferment and develop the right flavor profile.
Basically the take home message is that you need to be
patient no matter what path you follow. Then you may be
rewarded with an outstanding end product and then again you
might not. The brewing of lambic - style beers can provide
a whole new avenue to your brewing hobby. One that I think
you find well worth taking. Other Topics for General
Audience Discussion.

What really is it that makes a good lambic? Lambic, gueuze,
fruit varieties Extract approach and all grain approach
Discussion of Blending and its effect Who drinks lambic and
why.